Subspecies: Somewhere between 5 and 9 races (subspecies) of the Eastern Screech-Owl are defined and accepted. We define 6 of these races in following with that which is most commonly accepted. The Eastern Screech-Owl generally increase in size from south to north and color intensity from west to eastM. a. maxwelliae is found west of the Great Lakes in South-Central Canada and the North-Central US. South to N.E. Colorado and N.W. Kansas.M. a. hasbroucki is found from C. Kansas south to Oklahoma and Texas.M. a. mccallii is found from S. Texas to the southern border of Tamaulipas, Mexico.M. k. floridanus is found in Florida and west along the Gulf coast to Louisiana.M. a. asio is found in South Carolina, Georgia, Virginia, and Oklahoma.M. a. naevius is found in S. E Canada and N.E. US. (sometimes combined with M. a. asio).

Description: The Eastern Screech has three color morphs, red, brown, and gray. Red color morphs are more common in the south and the gray color morphs are more common in the north. The brown color morph is an in-between color form that is much less common than the other two color morphs. These color forms are more of “a percentage” in that both red and gray color morphs are found throughout most of their range. A small owl, the Eastern Screech-Owl varies significantly in size. The smallest race (subspecies) is the mccallii from S. Texas and N.E. Mexico. This is also the only race that has only one color morph, gray. The largest race is the naevius from the N.E. US and S.E. Canada. In aggregate, the Eastern Screech-Owls become larger as you go north in their range and the percentage of red color morphs become more prevalent as you head east in their range. In appearance, the sexes of the Eastern Screech-Owls are the same. Separation between Eastern and Western Screech-Owls can only be done reliably by sound. It was not until 1983 these two species were formally split. The Eastern Screech-Owl has a little longer ear tufts and bill. The bill is never black and more of a greenish-olive color. In general, it is slightly more vivid in plumage than its western counterpart, has a more prominent blackish rim to its facial disk, and its underparts are slightly less coarsely patterned.

Habitat:

The Eastern Screech-Owl is thought to be the most abundant owl east of the Rocky Mountains. Unlike its Western Screech-Owl twin, this species is a very common as a backyard raptor in urban areas. Commonly found in city parks, forested stream sides, and suburban areas with large shade trees. Gehlbach, a noted screech-owl researcher in Texas, even found evidence that Eastern Screech-Owls do better in suburbia than they do in the countryside, having higher survival rates and greater longevity. Eastern Screech-Owl distributions are positively associated with habitat edge, running water and wet woodlands. In the north, they are not often found above 2,000 feet in elevation and above 5,000 in Mexico. Low densities are associated with unbroken heavily wooded areas. Studies in Winnipeg Canada detected almost two thirds of all Eastern-Screech-Owls in moderate to high density suburban areas. This may reflect their greater success in areas of open parklike habitats with fewer large avian predators.

Food and Feeding:

With somewhat larger feet and a longer bill than the largely insectivorous Western Screech-Owl, the Eastern Screech-Owl is more dependent on vertebrate prey. Nevertheless, this owl enjoys a very wide spectrum of food including invertebrates, amphibians, and reptiles. Usually hunting from a perch and pouncing on prey, it seems to take that which is most available, including prey that is substantially larger than it is. Most of its prey is small rodents but the owl is not opposed to wading into water for small fish or crayfish. The Eastern Screech-Owls diet also varies with the season. Studies have shown up to 68% of its diet being small birds during the breeding season. This ferocious little owl has a meal menu of mammals that include chipmunks, mice, rats, shrews, moles, flying squirrels, and even bats. Its appetite for birds is even greater and is not only comprised of songbirds but may include nonpasserines such as Northern Bobwhite, American Woodcock and even prey as large as Ruffed Grouse. Its feeding ferocity doesn’t exclude other avian predators either. Prey such as the smaller Saw-whet Owl, or American Kestrel, and even other screech-owls are included.

Breeding:

Eastern Screech-Owl is a secondary cavity nester depending on old woodpecker or flicker holes and natural tree cavities for nesting. They mate for life but with a high mortality rate the owls will take a new mate when it loses its previous mate. Studies show this leads to a high turnover rate each year. Breeding season is largely independent of latitude and most egg laying happens in April although scattered records range from about two weeks either side of this month.

Clutch size can vary from 1 to 8 eggs although averages 3 to 4. Incubation period averages about 26 days and fledging averages about 30 days thereafter. The adults continue to care for the young for about an additional two months.

Movements and Life Span:

Contrary to the claims that in the far north of their range Eastern Screech-Owl may migrate, there is no evidence of this. In studies in Northern Ohio, which would represent the owl’s northern range extents, even juvenile dispersal only averaged a mere 20 miles. These dispersals happen in early fall when winter movements would peak. Adult movements of banded birds were half this and none moved more than 40 miles.

The oldest recorded wild Eastern Screech-Owl was an owl in Ontario that had been banded and then recovered dead for estimated age at death of 14 years 6 months. Captive owls have been recorded to live for over 20 years. In general, wild owls do not often live beyond about five years.